Charles Ellicott Commentary Leviticus 9:12

"And he slew the burnt-offering; and Aaron`s sons delivered unto him the blood, and he sprinkled it upon the altar round about." — Leviticus 9:12 (ASV)

And he slew the burnt offering. —As was the order of the sacrifices which Moses brought , so here the sin offering is followed by the burnt offering. The ram which constituted this sacrifice Aaron slaughtered at the north side of the altar , and after the blood had been received into the bowl by his sons who assisted him, and had been handed to him, Aaron sprinkled it around the altar in the same manner as Moses had done before. .